1. Field of the Invention
This invention relates to a lens module, and more particularly to a lens module used in mobile electronic products.
2. The Related Art
With the popularity of camera phones, the quality of photography has become one of the main considerations for consumers to purchase a new mobile phone having a lens module therein. In order to make photographic quality of the lens module better and the size and the weight of the mobile phone slimmer, the allowable error value of assembling optical lens of the lens module is also getting strict. Take a general two-megapixel camera lens for an example, the eccentric error while assembling the optical lenses must be less than 3 μm.
Referring to FIG. 1, a conventional lens module includes a lens housing 90 and several optical lenses 91 mounted in the lens housing 90. Each of the optical lenses 91 includes a refractive portion 92 closed to the optical axis 94 and a positioning portion 93 away from the optical axis 94. The optical lens 91 is assembled and fixed in the lens housing 90 by means of the positioning portion 93. So the manufacturing error of the lens housing 90 will affect the assembling error of the optical lens 91. Therefore, in order to reduce the assembling error of the optical lens 91, the manufacturing error of the lens housing 90 must be controlled in a sufficiently small value. However, since the manufacture process and the mold precision of the optical lens 91 are different from that of the lens housing 90, the lens housing 90 often has a higher manufacturing tolerance than the optical lens 91. It causes a higher assembling error of the lens module and a lower production yield.
In view of these disadvantages above, the structure of the conventional lens module needs to be improved.